The enthalpy change of formation, $\Delta H_f$, for hydrated calcium ions is the enthalpy change for the reaction below. $\text{Ca(s)} + \text{aq} - 2e^- \rightarrow \text{Ca}^{2+}(\text{aq})$ These enthalpy changes are not given in the Data Booklet. $\text{Ca(s)} \rightarrow \text{Ca(g)} \quad \Delta H_a = 177\,\text{kJ mol}^{-1}$ $\text{Ca}^{2+}(\text{g}) + \text{aq} \rightarrow \text{Ca}^{2+}(\text{aq}) \quad \Delta H_{hyd} = -1565\,\text{kJ mol}^{-1}$ Calculate the enthalpy change of formation of hydrated calcium ions.
- A$-1388\,\text{kJ mol}^{-1}$
- B$-798\,\text{kJ mol}^{-1}$
- C$-238\,\text{kJ mol}^{-1}$
- D$+352\,\text{kJ mol}^{-1}$